Spark-plug.



H. E. MAHEE.

SPARK PLUG.

APPLICATION FILED APR.28,1910.

Patented. Feb. 7, 1911.

HARRY ELLSWORTH MAHER, F CROOKSTON, MINNESOTA.

SPAItK-PLUG Specification of Letters Patent.

Batented Feb. 7, 1911.

Application filed April 28 1910. Serial No. 558,191.

To all whom it may concern:

Be it known that I, HARRY ELLswoR'rH' MAHER, a citizen of the United States, re-

- siding at Crookston, in the county of Polk and State of Minnesota, have invented certain new and useful Improvements in Spark- Plugs, of which the following is a specification.

It has long been a desideratum in the art ofconstruction of spark plugs for explosive engines, to provide a device of this class which is self-cleaning, so to speak, or in which soot, .oil, or foreign matter tending to collect in the spark gap will be discharged during the operation of ignition of the explosive charge, thereby keeping the plug in constant condition for eflicient service.

While I am acquainted with practically all the spark plugs on the market, I have never seen one which is really self-cleaning, or which will not clog atthe spark gap, causing missing of the explosion of the I motor and other disadvantages obvious to tion; Fig. ,2 is an end elevation of the central of porcelain, the latter having an annular those acquainted with the operation of internal combustion engines.

It has therefore been the object of my invention to supply a spark plug embodying a' central electrode as customary, the latter in my invention being peculiarly constructed to accomplish the results before described.

For a full understanding of the present invention, reference is to be had to the accompanying drawings, in which- Figure 1 1s a central vertical sectional view of a spark plug embodying the invenelcctrode.

Throughout the following detail description and on the several figures of the drawings similar parts are referred to by like reference characters.

In the general construction of my plug, the main parts are similar to those commonly in use and comprise the outer shell 1 to be screwed into the engine cylinder, havinga suitable insulating core 2 preferably enlargement 2 adapted to be seated against shell or'casing 1'.

a gasket 3 interposed between the enlargement 2 and an internal shoulder 4 on the The core 2 is held in place by a retaining nut 5. Passing through the core 2 is a" central electrode rod 6 at the lower end of which is provided the central electrode 7, of the spark plug, the latter being integrally or otherwise connected with the rod 6. A metallic cap 8 and the usual binding nut 9 arescrewed on theupper end of the rod 6 for the usual purposes and the lower end of the core 2 has a longitudinal recess 2 in which a packing l0 and packing nut 11 are arranged.

The construction of the electrode 7 is of primary importance to the present invention, said electrode consisting of an approximately circular body formedinits periphery with a V-shaped groove 7 by which are provided spaced flanges 7 and 7 the latter being in spaced relation to, but received in the lower end of the casing 1. The flange 7 is spaced closer to the casing 1 than the flange 7 and the two flanges form two spark gaps, the operation and advantages of which will now be described.

In the operation of the plug under normal conditions the flange 7 being closer to the casing 1 than the adjacent flange 7 the s arks ordinarily jump the gap betweenthe ange 7* and the casing and the ignition of compressed gas in the cylinder takes place at this point, and the exploded gases expand in the V-shaped groove 7 passing outwardly at very high velocity, carrying with it any deposits of oil or soot entering the end of the spark plug or between the gap 7 b and the casing 1. The lower spark gap at the flange 7 is thus kept free or clean, soot and foreign deposits being automatically cleared therefrom, so to speak, in the operation of the invention. Thus should the spark fail to cross the gap at the flange 7 for any reason, the flange 7 provides an auxiliary gap, insuring proper sparking and ignition of the gas to obtain best results.

Naturally, also, the ignition of the compressed gas at the gap near the flange 7 will tend to clear the gap at the flange 7 with most advantageous results. Furthermore, the rush of the gas from within the casing 1 when ignition takes place tends to create a vacuum above the electrode 7, thereby drawing all foul gas out of the cavity at said point, the self-cleaning operation of the invention being thus subserved. By the use of the invention the explosive charge will ing in running expenses and permitting the engine to run cooler with a weaker mixture. The terms upper and lower as used K herein are to be understood as relative, more especially in the sense of inner and outer,

respectively, and in reference to the position of the flanges of the electrode 7. Having thus described my invention, what is claimed as new, is:' e

1. In a spark plug, the combination of a casing, an electrode mounted therein and comprising a body spaced from the casing and provided with upper and lower spaced flanges, each of which are spaced from the casing to form spark gaps. 2. In a spark plug, the combination of a casing, an electrode mounted in an end there-' flat body spaced from of and comprlslng a the casing and provided with upper and lower spaced flanges each of which are spaced from the casing to form spark gaps,

and the upper flange havingits edge spaced closer to the casing than the Edge of the lower flange.

3. In a spark plug, casing, thereof and comprising a flat round body formed in its periphery with a V-shaped groove providing upper and lower flanges and an intermediate space, the flanges being unequally spaced from ing to form two spark the coinbination of a gaps, the one acting auxiliary to the other. a I

In testimony whereof I aflix, my signature in presence of two witnesses. HARRY ELLSWORTH MAHER.

Witnesses: i v I I A. A. MILLER, L. S. MILLER.

the sides of the casan electrode mounted in an end, 

